Efficient processing of images is increasingly important for online search engines. Many existing search engines examine images that are available via the Internet and include potentially relevant images in their search results. Examination of an image in connection with an Internet search typically requires analyzing an annotation or other text associated with the image. For example, an image of the Empire State Building may be stored with several annotations, including “Empire State Building,” “skyscraper,” “building,” “structure,” “New York City,” etc. However, current methods for annotating images are inefficient and slow. For example, many existing systems require manual annotation of images.